# Photons Energy Level

1. May 14, 2008

### Air

I understand that electrons are excited to higher energy levels. When they fall back levels, photons are emitted.

If green light has wavelength $5.58 \times 10^{-7}m$ and red light has wavelength of $6.48 \times 10^{-7}m$, why is it that when a photon is emitted from green light, it falls a greater energy level?

2. May 14, 2008

### Mapes

What is the relationship between energy and wavelength for electromagnetic waves?

3. May 15, 2008

### Air

$v = f \lambda$
$E = hf = \frac{hv}{\lambda}$

So green light has a smaller wavelength hence a larger value of energy. Is this why it falls a greater energy level?

4. May 15, 2008

### Defennder

Yes, that is so.

5. May 15, 2008

### atom888

so... if E=hf, green light have more energy than red light?

6. May 15, 2008

### Defennder

Yes, but that energy is per photon.